github: bump actions/checkout from 2 to 3

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 3.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v2...v3)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/build.yml

@@ -16,7 +16,7 @@ jobs:
         operating-system: [ ubuntu-latest, windows-latest, macos-latest ]
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: Install Rust (stable)
       uses: actions-rs/toolchain@v1
       with:
@@ -40,7 +40,7 @@ jobs:
     name: Check formatting
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: nightly
@@ -57,7 +57,7 @@ jobs:
     permissions: write-all
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: stable
@@ -74,7 +74,7 @@ jobs:
     permissions: write-all
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: nightly

.github/workflows/nix-linux.yml

@@ -14,7 +14,7 @@ jobs:
     name: nix-build
     timeout-minutes: 20
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
         with:
           fetch-depth: 0
       - uses: cachix/install-nix-action@v16

.github/workflows/scorecards.yml

@@ -22,7 +22,7 @@ jobs:
 
     steps:
       - name: "Checkout code"
-        uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # v2.4.0
+        uses: actions/checkout@v3 # v2.4.0
         with:
           persist-credentials: false